Derivative Financial Instruments - Effect of Derivative Instruments on Consolidated Statement of Income Derivative in Cash Flow Hedging Relationship (Detail) (Cash Flow Hedging [Member], Interest Rate Contracts One [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash Flow Hedging [Member] | Interest Rate Contracts One [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Loss Recognized in Other Comprehensive Income on Derivative (Effective Portion)	$ (146)	$ 285